在Wince/WM实现进程间通信

本文来自http://blog.youkuaiyun.com/hellogv/ ，引用必须注明出处！

最近在做WM上的进程间通信，使用WindowMessage实现两个进程间的通信，感觉MessageWindow不太好用，所以就用别的方法实现接收WindowsMessage。本文的代码大部分来自网络，东凑西凑才拼成本文。

先来封装一下需要使用的功能，命名为Cls_Message:

using System; using System.Collections.Generic; using System.Text; using System.Runtime.InteropServices; using Microsoft.WindowsCE.Forms; using System.Windows.Forms; class Cls_Message { private struct COPYDATASTRUCT { public int dwData; public int cbData; public IntPtr lpData; } //------------------------------------------------------------------------------- private const int WM_COPYDATA = 0x004A; private const int GWL_WNDPROC = -4; private const int LMEM_FIXED = 0x0000; private const int LMEM_ZEROINIT = 0x0040; private const int LPTR = (LMEM_FIXED | LMEM_ZEROINIT); private IntPtr oldWndProc = IntPtr.Zero; private WndProcDelegate newWndProc; private IntPtr formHandle; //------------------------------------------------------------------------------- delegate IntPtr WndProcDelegate(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam); [DllImport("coredll.dll")] static extern IntPtr CallWindowProc(IntPtr lpPrevWndFunc, IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam); [DllImport("coredll.dll", EntryPoint = "GetWindowLong")] private static extern IntPtr GetWindowLong(IntPtr hWnd, int nIndex); [DllImport("coredll.dll")] static extern int SetWindowLong(IntPtr hWnd, int nIndex, IntPtr newWndProc); [DllImport("coredll.dll", EntryPoint = "FindWindow")] public static extern IntPtr FindWindow(string lpClassName, string lpWindowName); [DllImport("coredll.dll")] private static extern int SendMessageW(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam); [DllImport("coredll.dll")] private static extern IntPtr LocalAlloc(int flag, int size); [DllImport("coredll.dll")] private static extern IntPtr LocalFree(IntPtr p); /// <summary> /// 初始化消息类 /// </summary> /// <param name="handle">接受消息的窗体的句柄</param> public Cls_Message(IntPtr formHandle) { this.formHandle = formHandle; newWndProc = new WndProcDelegate(WndProc); oldWndProc = GetWindowLong(formHandle, GWL_WNDPROC); int success = SetWindowLong(formHandle, GWL_WNDPROC, Marshal.GetFunctionPointerForDelegate(newWndProc)); } /// <summary> /// 消息处理 /// </summary> private IntPtr WndProc(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam) { if (msg == WM_COPYDATA) { COPYDATASTRUCT st = (COPYDATASTRUCT)Marshal.PtrToStructure(lParam, typeof(COPYDATASTRUCT)); string str = Marshal.PtrToStringUni(st.lpData); MessageBox.Show(str); } return CallWindowProc(oldWndProc, this.formHandle, msg, wParam, lParam); } static private IntPtr AllocHGlobal(int cb) { IntPtr hMemory = new IntPtr(); hMemory = LocalAlloc(LPTR, cb); return hMemory; } static private void FreeHGlobal(IntPtr hMemory) { if (hMemory != IntPtr.Zero) LocalFree(hMemory); } /// <summary> /// 发送消息 /// </summary> /// <param name="formTitle">目标窗体的名称</param> /// <param name="message">消息内容</param> static public void SendMessage(String formTitle,String message) { IntPtr hWndDest = FindWindow(null, formTitle); COPYDATASTRUCT oCDS = new COPYDATASTRUCT(); oCDS.cbData = (message.Length + 1) * 2; oCDS.lpData = LocalAlloc(LPTR, oCDS.cbData); Marshal.Copy(message.ToCharArray(), 0, oCDS.lpData, message.Length); oCDS.dwData = 1; IntPtr lParam = AllocHGlobal(oCDS.cbData); Marshal.StructureToPtr(oCDS, lParam, false); SendMessageW(hWndDest, WM_COPYDATA, IntPtr.Zero, lParam); LocalFree(oCDS.lpData); FreeHGlobal(lParam); } }

接下来贴出调用代码，实现自发自收，如果要发给别的进程，只需要把SendMessage的第一个参数改为目标窗体的名称即可（当然目标窗体也必须引用了Cls_Message实现收信息处理）：

Cls_Message clsMessage;//初始化 public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { clsMessage = new Cls_Message(this.Handle);//使本窗体能够接收WindowMessage } private void button1_Click(object sender, EventArgs e) { Cls_Message.SendMessage("Form1", "hello form1"); }